]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
ocfs2: avoid system inode ref confusion by adding mutex lock
authorjiangyiwen <jiangyiwen@huawei.com>
Thu, 3 Apr 2014 21:47:13 +0000 (14:47 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 3 Apr 2014 23:20:57 +0000 (16:20 -0700)
commit43b10a20372d9a1c08391f33f1c8bd86179ddc5f
treeed5fd7ca5fd34c4d84393e7fb3d65b8512594382
parent7dc3e83901b342ea7fe36262329c3784f2937361
ocfs2: avoid system inode ref confusion by adding mutex lock

The following case may lead to the same system inode ref in confusion.

A thread                            B thread
ocfs2_get_system_file_inode
->get_local_system_inode
->_ocfs2_get_system_file_inode
                                    because of *arr == NULL,
                                    ocfs2_get_system_file_inode
                                    ->get_local_system_inode
                                    ->_ocfs2_get_system_file_inode
gets first ref thru
_ocfs2_get_system_file_inode,
gets second ref thru igrab and
set *arr = inode
                                    at the moment, B thread also gets
                                    two refs, so lead to one more
                                    inode ref.

So add mutex lock to avoid multi thread set two inode ref once at the
same time.

Signed-off-by: jiangyiwen <jiangyiwen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/ocfs2/ocfs2.h
fs/ocfs2/super.c
fs/ocfs2/sysfile.c